Team Penske's Helio Castroneves went straight from Sunday's IndyCar championship showdown in California to the Sebring circuit in Florida to get his first taste of the Acura ARX-05 DPi. By all accounts, the three-time Indy 500 winner loved the experience.

"He did," Penske president Tim Cindric told RACER. "We were able to get him out there and get him a flavor for it. We were a bit concerned about the condition of the track after the hurricanes, but that turned out to be OK. So, we were able to shake down there and spend a couple days there understanding what we don't know. That track shakes a lot of bugs loose."

Although the 42-year-old came up short in his title bid against teammate Josef Newgarden, returning to Sebring – the site of a podium result for Castroneves in 2007 driving one of Penske's Porsche RS Spyders – seemed to uplift his mood.

"It was fun; the car is awesome," he told RACER. "I was very impressed. It was more to get acclimated, to learn the brakes, all the different stuff, so I could get some seat time. And who doesn't want to drive with Juan [Pablo] Montoya? I was like, 'I miss you, man! It's a blast being together again."

Penske's Montoya and Action Express Racing's Dane Cameron were the first two drivers confirmed for the ARX-05 program. Montoya has been tasked with most of the testing duties while Cameron awaits the end of the season before his contract with AXR is completed so he can join in the development process.

Castroneves is expected to be confirmed as another full-time driver at some point during the offseason.

"It's good to keep your mind going, learning something else," said Castroneves. "We were disappointed not to win the [IndyCar] championship. We didn't win the strategy [at Sonoma], and I'm bummed out for not winning it, but I'm happy for the team. It was fun to get right back in a car, something different, and keep the momentum going."

Castroneves could be back in a prototype tomorrow at Road Atlanta, and if that test is completed successfully, Team Penske will likely go forward with its plan to enter a WEC-spec ORECA 07-Gibson at the Petit Le Mans IMSA season finale.

"If everything cooperates, we're planning to be on track tomorrow, the 21st," Cindric added. "We'll regroup after that and make a decision and go on."